There are two AMDIS libraries in the set: UNK-DB5MSRI and UNK-DB5RI.  
Both have a CID and MSL file.

The data in the UNK-DB5MSRI library uses the RI values from the DB5MS set.  
It also includes a few additional unknowns that were found in the analysis 
of NIST SRM reference urines.  These are not present in the DB5 set.

NOTE: The CAS numbers given ARE NOT legitimate values.  They are simply 
numbers that satisfy the CAS check sum.  The values are all above the 
largest CAS number at the time of the original publication.